I already did. Please see thread opener.
As already said, the effect is not always reproducable. I have no idea, which circumstances must be fullfilled for a safe reproducability.

But it is 100% not a problem with my browser (effect occurs with different browsers, even with cleared cache+cookies, even without any add-ons) or with my internet connection:
Just now I got a message from Reader, that there are 2 new posts. I clicked the button and yes, there were 2: two instances of the same post (this time that one http://inognisenso.wordpress.com/2013/02/27/weekly-photo-challenge-forward/ )